Accompanied by an increase in traffic injuries, accidents, and the growth of an aging population conditions such as fractures, tumors, degeneration, and aging of the spine are also increasing. Medical treatment and physiotherapy cannot cure most of the patients suffering from these conditions. Therefore, surgical treatment is often needed. During the operation, the fixation systems and instruments are usually required to stabilize and remedy a deformed spine. Essentially, a good spinal implant must meet the following conditions: (1) have good rigidity when assembled; (2) have sufficient stability when fixed to the spine; (3) be adaptable to accommodate spinal deformity, and (4) be easily and safely applied to the spine.
At present, anterior spinal fixation systems are primarily used for burst fractures, spinal tumors, spinal deformities, and degenerative diseases. They should be of low profile and easy for the surgeon to apply.
Clinically, the anterior spinal body is located close to the aorta. This increases the difficulty of performing an anterior surgical operation. Therefore, the use of an anterior spinal fixation systems must have as a primary consideration absolute safety. Another consideration is, to reduce operation time and simplify the operational steps.
U.S. Pat. No. 5,330,473 discloses a connector for a spinal fixation systems, adapted to for connecting two supporting rods. However, it is used to connect the posterior fixation system, not the anterior fixation system.
U.S. Pat. No. 5,620,433, discloses an anterior screw-supporting rod connector, which has upper and lower bolts. This connector cannot be assembled easily.
The Kaneda Device is appreciated by surgeon as one of the best available fixation systems, and is characterized by lateral fixation, including vertebral steel plates, vertebral screws, nuts, supporting rods, and a transverse fixation system. The Kaneda Device allows correction of deformities and provides sufficient rigidity, which is particularly useful when used in operating on spinal fractures, and recovering from a resection spinal tumor operation. However, there is still a need to provide an improved device to resolve the following deficiencies: (1) The Kaneda Device is complicated in use due to its lateral fixation; (2) The laterally-extending supporting rods of the Kaneda Device increase risk during to the operation.
The purpose of the present invention is to resolve the aforesaid deficiencies of the prior art, while at the same time providing an anterior spinal fixation system, which is as the rigid as Kaneda device and also easy to be installed.